The present invention relates generally to welding systems and, more particularly, to a welding-type apparatus designed for portability. The welding-type apparatus includes an interchangeable energy storage device to generate a power output for a selectable welding-type process.
Power driven tools make up a large percentage of consumer and commercial tools. Traditional power driven tools receive driving power from corded attachment to a power receptacle. However, it is generally known that cordless tools that are not restricted by cords or cables for operation are preferred. As such, power tools driven by an energy storage device, typically a battery, have become an industry mainstay. Such battery driven power tools, or “cordless” power tools, allow for the use of the power tool where and when transmission or engine driven power is unavailable or impractical.
However, while cordless power tools are pervasive in the market, there are specific areas of the tool market that have yet to successfully adapt the tool to be driven by an energy storage device. Often, while cordless power tools are preferred, the cordless version of the traditional power tool usually includes a performance drop. For example, cordless power tools often operate at a lower power than the traditional counterpart. Furthermore, cordless power tools require frequent recharging that may interfere with a user's desire to utilize a cordless power tool to perform an extensive undertaking. That is, to complete an extensive undertaking the user must make frequent breaks to recharge a depleted battery else keep multiple batteries on-hand to be interchanged with depleted batteries.
Additionally, many traditional power driven tools require power levels above levels feasibly attained from energy storage devices. That is, the battery configurations required to supply the level of power necessary to effectively utilize the power tool would be overly cumbersome so as to render the power tool effectively non-portable.
For example, a typical welder designed for Shielded Metal Arc Welding, generates an output open circuit voltage between 45 and 75 volts, while a typical welder designed for Gas Metal Arc Welding generates an output open circuit voltage between 30 and 45 volts. To deliver comparable performance when powered from an energy storage device, multiple batteries would be required. Specifically, to generate the maximum desired open circuit voltage of 75 volts, a combination of seven traditional 12 volt batteries would be required. However, the inclusion of seven traditional 12 volt batteries in a “portable” MIG welder would render the device too cumbersome to be portable. Additionally, such a welder would not be cost effective.
To overcome this problem, welders have been developed that operate within the desired output range with a minimized battery configuration that still permits portability. Specifically, an output of the battery configuration is connected directly to the output of the welder to allow maximum power transfer. However, such minimized battery configurations significantly limit the duration of operability of the welder. Specifically, operational duration may be limited to a few minutes at maximum operational power output. Furthermore, by directly connecting the output of the battery configuration to the welding output, the user is precluded from regulating the voltage output of the welder to tailor the welding process to the specific welding task.
It is therefore desirable to design a portable welder that provides an open circuit voltage comparable to traditional, corded, welders. Additionally, it is desirable to design a portable welder that includes output voltage or current control. Furthermore, such a welder should be cost effective and efficient to be attractive to the end user.